Title of Invention	"DEVICE FOR DRIVING MESHING NEEDLES AND WEAVING LOOM EQUIPPED WITH SUCH A DEVICE"
Abstract	This device comprises an electric rotary actuator (6) of which the output shaft (7) is kinematically connected, by means (8, 9) for transforming a rotary movement (F5) into a translational movement (F2), to a plurality of meshing needles (5).

Full Text

The invention relates to a device for driving meshing needles for a sickle-type weaving loom. The invention also relates to a weaving loom equipped with such a device. In the domain of sickle-type weaving looms, it is known to use, for the formation of selvedges of fabrics or ribbons in the course of manufacture, so-called meshing needles which operate by reciprocating advance and return movements in synchronism with the movement of the sickles, and this in order to hook the weft yarn brought by a sickle and to mesh it with the preceding weft. Such meshing needles are generally provided with a latch and controlled by devices incorporating cams and connecting rods which must be adjusted precisely in order to fix the amplitude and the extreme positions of the stroke of these needles. These drive and control devices are complex and relatively unreliable. In addition, they are expensive and are long and delicate to adjust, which does not enable satisfactory precision and repetitivity of the movement of the meshing needles to be obtained. It is a particular object of the invention to overcome these drawbacks by proposing a novel device for driving meshing needles, which is easily adjustable and which does not tend to malfunction in the course of time, while its construction is more simple than that of the known devices, this rendering it more reliable. In this spirit, the invention relates to a device for driving meshing needles in a sickle-type weaving loom, which comprises an electric rotary actuator of which the output shaft is kinematically connected, by means for transforming a rotary movement into a translational movement, to a plurality of meshing needles. Thanks to the invention, the movement of the meshing needles may be adjusted extremely rapidly and precisely, by playing on the parameters for controlling the electric rotary actuator. In addition, the fact of controlling a plurality of needles thanks to the same actuator makes it possible to limit the number of components of the drive device, this reducing its cost and improving its reliability. The device of the invention can operate at high speed, particularly higher than the connecting rod/cam systems of the state of the art, while its space requirement is reduced. The linear movement of the meshing needles parallel to the selvedge of the fabric or of the ribbon during weaving makes it possible to produce less high meshes and to reduce the necessary compensation. According to advantageous but non-obligatory aspects of the invention, a meshing needle drive device may incorporate one or more of the following characteristics taken in any technically admissible combination: - The movement transformation means are distributed over the length or in the longitudinal direction of the aforementioned shaft and make it possible each to drive a meshing needle. In that case, the position of these movement transformation means along this shaft is advantageously adjustable, this allowing an easy displacement of the meshing needles weftwise, therefore an adjustment of the width of the woven fabric or ribbon. - According to a first form of embodiment, the device comprises at least one pinion driven in rotation by the aforementioned shaft and in mesh with a rack fast with a meshing needle. This pinion is advantageously mounted to slide with reduced clearance along the aforementioned shaft. This shaft may have a non-circular outer section, while the pinion is provided with an opening for passage of the shaft which has a profile at least in part substantially complementary of its section. For example, the shaft may be provided to be fluted, while the pinion has a likewise fluted central opening. - According to a second form of embodiment of the invention, at least one flexible element is fastened and partially wound around the shaft, this flexible element being connected to a meshing needle or to a member for driving such a needle in translation. - According to a third form of embodiment of the invention, the aforementioned shaft is equipped with at least one element projecting radially, particularly of connecting rod or cam type, which extends outwardly with respect to the aforementioned shaft and which is coupled to one of the meshing needles or to a member for driving such a needle in translation. - Whatever the embodiment, the meshing needle is advantageously removably connected on the rack or on its drive member. The invention also relates to a sickle-type weaving loom equipped with a drive device as described hereinabove. Such a loom is easier to manufacture, to adjust and to maintain than those of the state of the art and can operate at higher speed. The invention will be more readily understood and other advantages thereof will be more apparent in the light of the following description of three forms of embodiment of a drive device in accordance with its principle, given solely by way of example and made with reference to the accompanying drawings, in which: Figure 1 is a schematic representation in perspective of a part of weaving loom according to the invention incorporating a device for driving meshing needles according to the invention. Figure 2 is an exploded view in perspective of a part of the device of Figure 1. Figure 3 is a view in perspective of a part of a device according to a second form of embodiment of the invention. Figure 3 A is a partial view on a larger scale in the direction of arrow IIIA in Figure 3, and Figure 4 is a view similar to Figure 3 for a device according to a third form of embodiment of the invention. The weaving loom M shown partially in Figure 1 makes it possible to weave in parallel a plurality of ribbons R by intersecting warp yarns 1 and weft yarns 2. For each ribbon R, the waft yarns are more or less spaced apart from one another, forming a shed F, this shed being, for example, obtained by means of a Jacquard-type mechanism, known per se and not shown. For each ribbon, the weft yarn 2 is supplied from a reel (not shown) and introduced in the shed F by means of a sickle 4 animated by a reciprocating rotational movement Fj about a substantially vertical axis X-X1. The weft yam 2 passes in an eye 41 made in the vicinity of the free end 42 of the sickle 4 of which the mechanism for drive about axis X-X1 is not shown in order to render the drawing clearer. In order to retain the weft yarn at the level of the selvedge closest to the observer in Figure 1, a meshing needle 5 is associated with each sickle 4, this needle being animated by a reciprocating advance and return movement, represented by the double arrow F2, which is essentially parallel to the direction of advance of the warp yarns represented by arrow F3. The meshing needle may be of any known type and, for example, equipped with a latch 5 a. In order to drive the three meshing needles 5 shown in Figure 1, an electric rotary actuator 6 is provided, in the present case a brushless D.C. electric motor, of which the output shaft 7 is fluted and centred on a geometric axis Y-Y' globally perpendicular to axis X-X' and to the direction F3 of advance of the warp yarns. On the shaft 7 there are mounted pinions 8 in a number equal to the number of needles 5 to be driven, each of these pinions being intended to be in mesh with a rack 9 on which a needle 5 is connected. In practice, each rack is provided with a housing 91 for receiving a rear end 51 of a needle 5, as well as with a screw 92 for blocking this end 51 in this housing 91. In this way, each needle 5 is removably connected with a rack 9, this making it possible to proceed with a rapid and easy exchange of one or more needles 5 during maintenance operations on the loom M. As is more particularly visible in Figure 2, each pinion 8 is provided with a fluted central opening 81 whose geometry is substantially complementary of the flutes 71 of the shaft 7, so as to allow a rotational connection of the pinion 8 with the shaft 7 and a slide with reduced clearance of the pinion 8 along this shaft, parallel to axis Y-Y', as represented by double arrow F4. Each pinion 8 also comprises an outer toothing 83 adapted to cooperate with a long: i longitudinal toothing 93 of the rack 9 associated therewith. As a function of the rotation of the shaft 7 represented by the double arrow F5 in Figure 1, each of the meshing needles 5 is driven in its reciprocating movement F2. In this way, the elements 8 and 9 constitute means for transforming the rotary movement F5 of the shaft 7 into a translational movement F2 of the different needles 5. The needles 5 and the racks 9 associated therewith are guided in their movement of translation F2 by housings 10 in which the racks 9 are disposed and which are formed by two half-shells 10A and 10B of which the inner surfaces constitute guide rails parallel to the double arrow F2. These half-shells lOa and lOb for guiding a rack 9 each extend in a lug 1 la or 1 1b, these lugs together forming a bearing for receiving the pinion 8 associated with this rack. This contributes to the correct relative positioning of the pinion/rack assemblies. It will be understood that the amplitude and the speed of displacement of the different needles 5 are easily adjustable by an appropriate adjustment of the supply parameters of the motor 6. A single motor 6 makes it possible to control a plurality of needles 5, for example all the needles of the loom M. In a variant, and as a function of the number of ribbons to be woven, two or more than two motors may be used. Taking into account the mode of connection of the pinions 8 and the shaft 7 in rotation, the position of each of the pinions 8 along the shaft 7 is easily adjustable, this making it possible to adjust the position of the different needles 5 along this shaft, particularly in order to take into account the number of woven ribbons R or their respective widths. The invention has been represented with pinions 8 of which the opening 81 is substantially complementary of the flutes 71 over the whole periphery of the shaft 7. The section of the shaft and the profile of this opening may be provided to be complementary only over one angular sector, or several, which nonetheless allows the pinions to be efficiently driven. In the second form of embodiment of the invention shown in Figure 3, elements similar to those of the first embodiment bear identical references increased by 100. The output shaft 107 of a brushless motor 106 extends perpendicularly to the direction of advance F3 of the warp yarns 101 of a weaving loom M of which the sickles 104 have a reciprocating rotational movement FI about an axis X-X'. Each meshing needle 105 is wedged on a bar 111 which is connected to the shaft 107 by means of a cable 112 which is fastened on the shaft 107 by means of a wedging member such as a wedge 113 immobilized on the shaft 107 by a screw (not shown). The cable 112 surrounds the shaft 107 over at least one turn and its two ends 112A and 112B are respectively connected to the two ends 111A and 11 IB of the corresponding bar 1ll, with the result that the reciprocating rotational movement F5 of the shaft 107 is transmitted in the form of a reciprocating movement of translation F2 to the corresponding needle 105. As before, the supply parameters of the motor 106 make it possible to control the stroke of the needles 105. In addition, the elements 105, 111 and 112 may be displaced parallel to the longitudinal axis Y-Y' of the shaft 107. In the third form of embodiment of the invention shown in Figure 4, elements similar to those of the first embodiment bear identical references increased by 200. In this embodiment, a brushless motor 206 drives, in a reciprocating movement of rotation F5, an output shaft 207 on which connecting rods 215 are keyed and mounted to slide along the longitudinal axis Y-Y1 of the shaft 207. These connecting rods extend radially with respect to the longitudinal axis Y-Y' and are each associated by a rod 217 with a bar 211 on which a meshing needle 205 is mounted. According to a variant of the invention (not shown), each connecting rod 215 might be coupled by a rod 217 directly to a needle 205. As before, the supply parameters of the motor 206 make it possible to adjust the reciprocating stroke F2 of the needles 205 of which the position parallel to axis Y-Y1 is adjustable. Whatever the form of embodiment considered, a meshing finger may, if necessary, be associated with the sickle and with the meshing needle for weaving each of the ribbons R. Within the meaning of the present Application, the output shaft of an electric rotary actuator is a shaft driven by this actuator, whether it be question of a shaft directly connected to the rotor of the actuator or of a shaft connected to a shaft itself connected to such a rotor. Different types of electric rotary actuators may be used within the framework of the present invention and, in particular, step-by-step motors or any other actuator allowing a reciprocating rotary movement and of which the parameters of movement, such as the speed, the instantaneous position and the amplitude, are adjustable. We Claim: 1. Device for driving meshing needles in a sickle-type weaving loom, characterized in that it comprises an electric rotary actuator (6; 106; 206) of which the output shaft (7; 107; 207) is kinematically connected, by means (8, 9; 111, 112; 215, 217) for transforming a rotary movement (F5) into a translational movement (F2), to a plurality of meshing needles (5; 105; 205). 2. Device as claimed in Claim 1, wherein said means (8, 9; 111,112; 215, 217) for transforming movement (F5, F2) are distributed over the length of said shaft (7; 107; 207) and make it possible each to drive a meshing needle (5; 105; 205). 3. Device as claimed in Claim 2, wherein the position of said movement transformation means (8, 9; 111, 112; 215, 217) along (Y-Y') said shaft (7; 107; 207) is adjustable (F4). 4. Device as claimed in one of the preceding Claims, wherein it comprises at least one pinion (8) driven in rotation by said shaft (7) and in mesh with a rack (9) fast with a meshing needle (5). 5. Device as claimed in Claims 3 and 4, wherein said pinion (8) is mounted to slide (F4) with reduced clearance along said shaft (7). 6. Device as claimed in one of Claims 4 or 5, wherein said shaft (7) has a non-circular outer section (71), while said pinion (8) is provided with an opening (81) for passage of said shaft, said opening having a profile at least in part substantially complementary of said section. 7. Device as claimed in one of Claims 1 or 2, wherein it comprises at least one flexible element (112) fastened and partially wound around said shaft (107), said flexible element being connected to a meshing needle (105) or to a member (111) for driving a meshing needle in translation. 8. Device as claimed in one of Claims 1 or 2, wherein said shaft is equipped with at least one element (215) projecting radially, particularly of connecting rod or cam type, which extends outwardly with respect to said shaft and which is coupled (217) to one of said meshing needles (205) or to a member (211) for driving a meshing needle in translation. 9. Device as claimed in one of Claims 4 to 8, wherein said meshing needle (5; 105; 205) is removably connected on said rack (9) or said member (111). 10. Weaving loom (M) incorporating sickles (4; 104) equipped with a drive device (6-10; 106-112; 206-217) as claimed in one of the preceding Claims.

Documents:

994-DEL-2005-Abstract-(20-04-2010).pdf

994-del-2005-abstract.pdf

994-DEL-2005-Claims-(20-04-2010).pdf

994-del-2005-claims.pdf

994-del-2005-correspondence-other.pdf

994-DEL-2005-Correspondence-Others-(20-04-2010).pdf

994-del-2005-description (complete).pdf

994-del-2005-drawings.pdf

994-DEL-2005-Form-1-(20-04-2010).pdf

994-del-2005-form-1.pdf

994-del-2005-form-18.pdf

994-del-2005-form-2.pdf

994-DEL-2005-Form-3-(20-04-2010).pdf

994-del-2005-form-3.pdf

994-del-2005-form-5.pdf

994-DEL-2005-GPA-(20-04-2010).pdf

994-del-2005-gpa.pdf

994-DEL-2005-Petition-137-(20-04-2010).pdf